In the Player's Handbook 2nd printing (on Kickstarter now along with the new campaign book, Bitter Reach). If you have a PDF of that (from DriveThruRPG most likely) then that should be updated by now). Tomas said on KS that they might make an errata PDF for everyone that doesn't have PDF of the books (and thus haven't got the updated book), so hopefully that will happen.

I have the upated pdf but i can't spot any differences with the physical one... I'm sure that the pdf is updated because of goblin/nocturnal!

There is no difference with spellcasting, what I have noticed. The difference is how NPC uses WP.

In the Player's Handbook 2nd printing (on Kickstarter now along with the new campaign book, Bitter Reach). If you have a PDF of that (from DriveThruRPG most likely) then that should be updated by now). Tomas said on KS that they might make an errata PDF for everyone that doesn't have PDF of the books (and thus haven't got the updated book), so hopefully that will happen.

I have the upated pdf but i can't spot any differences with the physical one... I'm sure that the pdf is updated because of goblin/nocturnal!

There is no difference with spellcasting, what I have noticed. The difference is how NPC uses WP.

On the other hand, an NPC with Rank 2 can cast spells up to Power Level 2 (3-4 if they are Half-Elves and/or using Ingredients) every round, regardless of the number of WP the players happened to have at the beginning of the session.

I have had a reread for most of the spells and it seems this new approach to NPC spell power levels will work well, with only a few spells where PCs could get a clear upper hand but this is balanced by a PCs use of WP.

is there a collected PDF of the changes. I'd like to print them and put them in the books I have. It is annoying to have to always go back to the PDF.

Unfortunately, not at this time.

Another unlisted change to the Player's Handbook, Opposed Rolls (p.49):

Clarifying that the act of rolling on an opposed roll does not count as an action to the defender, and that "DODGING and PARRYING in close combat are technically not opposed rolls, as they require an action by the defender, and can be pushed."